Hi Richard,
On 2020/2/5 18:31, Richard Henderson wrote:
On 2/5/20 10:01 AM, Richard Henderson wrote:
On 2/5/20 8:17 AM, Zenghui Yu wrote:
Our robot reported the following compile-time warning while compiling
Qemu with -fno-inline cflags:
Why are you doing this?
I'm not sure why it was added in the building test. As you said,
there's just a arbitrary combination of compile flags.
In function 'load_memop',
inlined from 'load_helper' at /qemu/accel/tcg/cputlb.c:1578:20,
inlined from 'full_ldub_mmu' at /qemu/accel/tcg/cputlb.c:1624:12:
/qemu/accel/tcg/cputlb.c:1502:9: error: call to 'qemu_build_not_reached'
declared with attribute error: code path is reachable
qemu_build_not_reached();
^~~~~~~~~~~~~~~~~~~~~~~~
[...]
Of course, the assert is compiled out when optimization is off, which is the
only time we expect inlining to be off.
The patch isn't wrong, exactly, but I question whether we want to support
completely arbitrary combinations of compile flags.
It doesn't hurt to do the right thing, and you already have the
good approach :)
To follow up: if you *really* need to support -fno-inline, then perhaps the
correct patch is to change
- #ifdef __OPTIMIZE__
+ #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__)
extern void QEMU_NORETURN QEMU_ERROR("code path is reachable")
qemu_build_not_reached(void);
#else
#define qemu_build_not_reached() g_assert_not_reached()
#endif
within include/qemu/compiler.h.
Thanks for this. I've tested it with -fno-inlie and it indeed works.
I will send it as v2.
Thanks,
Zenghui
